WAEC 2018 CHEMISTRY ESSAY AND OBJECTIVE ANSWERS – MAY/JUNE

WAEC 2018 CHEMISTRY ESSAY AND OBJECTIVE ANSWERS

Get Your WAEC 2018 CHEMISTRY ESSAY AND OBJECTIVE ANSWERS – MAY/JUNE Via ProudlyLoaded

Our free waec answers we be drop here before Exam start

Loading...

*2018 waec chemistry theory answers*

By A² solutions team

1a)A compound is a substance that results from a combination of two or more different chemical element s, in such a way that the atom s of the different elements are held together by chemical bonds that are difficult to break
*A² solutions*
1b) -Temperature
– High pressure

1c)-Vanadium (v) oxide
-Nickel

*A² solutions team*

5a)
1.Water Gas
2.Producer Gas
ii)Water Gas
iii) Both the hydrogen and Carbon(ii) Oxide in water gas
burn in air to release a lot of heat,this makes it a better
fuel
Iv)
1.Producer Gas
02(g) + N2(g) + 2C(s)–>2CO(g) +N2 + heat
2.Water Gas
C(s) +H2O(g)–>CO(g) + H2(g)
5b(i)Thermoplastics can be soften repeatedly by heat and
remoulded..
Thermosets cannot be soften or melted by heat and
remoulded once they are formed
ii)i.Bakelite
ii.Polythene
iii)
1.Plastic items can be manufactured at very low costs by
using moulds and good manufacturing process
2.Raw materials for the manufacturing of plastics are
readily and cheaply available from the refining of crude Oil
3.Plastics can be tailor made to our exact requirements,
because of wide applications.
3a)
From the passage of steam through a mass of hot coke at
a very high temperature (about 1000 oC).
The water gas is mixed with more steam and passed over
iron
(III) oxide (as catalyst) at 450 o C. More hydrogen is
produced
and carbon(II) oxide gets oxidized to carbondioxide. I.e.
The carbondioxide is removed by dissolving the above
products in water under 30 atm pressure – CO2 dissolves.
The gas is then passed through copper(I) methanoate in
ammonia solution under pressure to absorb any trace of
carbon(II) oxide which might be present as impurity if not
removed – the hydrogen produced is pure.
3aii)
C (s) + H 2 O(g) → CO (g) + H 2(g)
3aiii)
I. by the action of a dilute strong acid on metals, such as
zinc:
Ii. by reaction amphoteric metals with a strong base, such
as sodium hydroxide:
Iii. by electrolysis of water:
3b)
I. Decrease in temperature shifts reaction towards product
side.
Ii. increase in pressure shifts reaction towards reactant
side.
Iii. Increase in concentration of CO product side.
3ci)
Condensation polymerisation is a process whereby many
small monomer molecules join together to form one large
polymer, with water, or some other small molecule formed
at the same time.
3cii)
I. polyamides
Ii. polyacetals
3ciii) CH3−COO−CH2−CH3,
3d)
Allotropy is the existence of a chemical element in two or
more forms, which may differ in the arrangement of
atoms in crystalline solids or in the occurrence of
molecules that contain different numbers of atoms.
3dii)
a) diamond,
b) graphite
3diii)
Diamond is used for cutting hard substance.
Graphite is used to
make brake linings, lubricants, and molds in foundries

A² solutions

1ai)

Fermentation is the process in which a substance breaks down into a simpler substance. Microorganisms like yeast and bacteria usually play a role in thefermentation process, creating beer, wine, bread, kimchi, yogurt and other foods. Fermentation comes from the Latin word fermentare, meaning “to leaven.
(2ci)
– Chemical and allied products industries
– sunshine oil and chemical industries
– Eleme petrochemical industries
(2cii) source of raw materials
Nearness to market
Source of amenities
(2ciii)
-Pollution of air (surrounding)
-Land excavation and improper with disposal
(2di)
Ag2O(s) +H2O2= 2Ag(s)+ O2(g)+H2O(l)
(2dii)
H2O2 + Cl2 => 2HCl(g) + 2H2)(l)
(2e)
-It is an inert gas
-It is slightly denser than air
-It is slightly soluble in water
5a)
1.Water Gas
2.Producer Gas
ii)Water Gas
iii) Both the hydrogen and Carbon(ii) Oxide in
water gas burn in air to release a lot of
heat,this makes it a better fuel
Iv)
1.Producer Gas
02(g) + N2(g) + 2C(s)–>2CO(g) +N2 + heat
2.Water Gas
C(s) +H2O(g)–>CO(g) + H2(g)
5b(i)Thermoplastics can be soften repeatedly
by heat and remoulded..
Thermosets cannot be soften or melted by heat
and remoulded once they are formed
ii)i.Bakelite
ii.Polythene
iii)
1.Plastic items can be manufactured at very
low costs by using moulds and good
manufacturing process
2.Raw materials for the manufacturing of
plastics are readily and cheaply available from
the refining of crude Oil
3.Plastics can be tailor made to our exact
requirements, because of wide applications.
3a)
From the passage of steam through a mass of
hot coke at
a very high temperature (about 1000 oC).
The water gas is mixed with more steam and
passed over iron
(III) oxide (as catalyst) at 450 o C. More
hydrogen is produced
and carbon(II) oxide gets oxidized to
carbondioxide. I.e.
The carbondioxide is removed by dissolving the
above products in water under 30 atm pressure
– CO2 dissolves.
The gas is then passed through copper(I)
methanoate in
ammonia solution under pressure to absorb
any trace of carbon(II) oxide which might be
present as impurity if not
removed – the hydrogen produced is pure.
3aii)
C (s) + H 2 O(g) → CO (g) + H 2(g)
3aiii)
I. by the action of a dilute strong acid on
metals, such as zinc:
Ii. by reaction amphoteric metals with a strong
base, such as sodium hydroxide:
Iii. by electrolysis of water:
3b)
I. Decrease in temperature shifts reaction
towards product
side.
Ii. increase in pressure shifts reaction towards
reactant side.
Iii. Increase in concentration of CO product
side.
3ci)
Condensation polymerisation is a process
whereby many
small monomer molecules join together to
form one large polymer, with water, or some
other small molecule formed at the same time.
3cii)
I. polyamides
Ii. polyacetals
3ciii) CH3−COO−CH2−CH3,
3d)
Allotropy is the existence of a chemical
element in two or more forms, which may
differ in the arrangement of
atoms in crystalline solids or in the occurrence
of molecules that contain different numbers of
atoms.
3dii)
a) diamond,
b) graphite
3diii)
Diamond is used for cutting hard substance.
Graphite is used to
make brake linings, lubricants, and molds in
foundries

How to Subscribe for the answer:

WHATSAPP – 09097349351

Subscription Will End 1 hours Before Each Exam Starts

NOTE:- Direct Mobile Candidates Gets Answers on their Phone number as SMS before Exam start.

Our free answer we be posted here by 8am

Kip Visiting this Page

Loading...

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

ProudlyLoaded.com © 2018
Do NOT follow this link or you will be banned from the site!